This invention relates to a needle guide apparatus to enable accurate insertion of a needle into the spinal area, particularly to aid chemonucleolysis procedures for non-surgical treatment of a herniated invertebral disc.
Certain chemicals have been discovered that dissolve nucleus pulposus material, the gelatinous substance within a vertibral disc. These agents, known generally as lysing agents, when injected into a herniated disc, cause the gelatinous material to dissolve, relieving pressure on nearby spinal nerves. Of the two principal applicable lysing agents, chymopapain and collagenase, chymopapain is used most frequently. Chymopapain is an enzyme derivative from papaya and has been found to dissolve the material forming the nucleus pulposus, without adverse affect on the surrounding annulus fibrosis or thin top and bottom plates of hyaline cartilage. Success from intradiscal injection of chymopapain has provided in many cases, an effective alternative to open back surgery for removal or repair of a herniated disc by a laminectomy procedure.
A major problem with chemonucleolysis procedures however, is the accurate placement of the needle into the nucleus pulposus of the herniated disc. Heretofore, needle placement is in part trial and error, often requiring up to one hour of a treating physcian's time to locate the tip of the needle at the desired point within the disc. In addition to the tedium of the procedure and wasted time, misplacement or repeated perforation can be harmful to the patient. This problem is resolved by the needle guide apparatus devised, which accurately guides and locates the needle at the desired spot in the disc.
The needle guide is primarily used in discolysis procedures, but may be used in other procedures where a substance is injected into a disc or other spinal region.